In the diagnosis and treatment of breast cancer, it is often necessary to remove one or more tissue samples from a suspicious mass. The suspicious mass is typically discovered during a preliminary examination involving visual examination, palpitation, X-ray, MRI, ultrasound imaging or other detection means. When this preliminary examination reveals a suspicious mass, the mass must be evaluated by taking a biopsy in order to determine whether the mass is malignant or benign. Early diagnosis of breast cancer, as well as other forms of cancer, can prevent the spread of cancerous cells to other parts of the body and ultimately prevent fatal results.
Where appropriate, a biopsy can be performed by a percutaneous method to avoid the significant trauma and risk of infection to the breast tissue that is caused by the alternative open surgical biopsy procedure. This procedure also reduces the possibility of leaving disfiguring results and minimizes recovery time for the patient. In addition, the patient will incur a lower financial expense because the open surgical technique is more difficult, and time consuming and involves a more complex recovery.
The disadvantages of the open surgical technique coupled with the odds that the lesion is benign present a disincentive for the patient to consent to the biopsy. The added discomfort alone is enough to cause many patients to take the risk that the lesion is benign. The acceptance of this risk can prove to be fatal for the minority of cases where the lesion is malignant. The availability of the percutaneous method further decreases the apprehension of patients and helps insure that they will proceed with receiving the medical care they require.
Percutaneous biopsies have been performed using either Fine Needle Aspiration or core biopsy in conjunction with real-time visualization techniques, such as ultrasound or mammography (X-ray). Fine Needle Aspiration involves the removal of a small number of cells using an aspiration needle. A smear of the cells is then analyzed using cytology techniques. Although Fine Needle Aspiration is less intrusive, only a small amount of cells are available for analysis. In addition, this method does not provide for a pathological assessment of the tissue, which can provide a more complete assessment of the stage of the cancer, if found. In contrast, in core biopsy a larger fragment of tissue can be removed without destroying the structure of the tissue. Consequently, core biopsy samples can be analyzed using a more comprehensive histology technique, which indicates the stage of the cancer. In the case of small lesions, the entire mass may be removed using the core biopsy method. Thus, core biopsy allows the construction of a more detailed picture the disease's progress and type. To further ensure that a complete picture is obtained, it is generally preferable to minimize tissue losses during the retrieval of biopsy cores from the biopsy device.
Certain biopsy devices are configured as an open system where the tissue discharge port is simply an open area of the device. A surgical assistant must remove the tissue from the open compartment using forceps and place the tissue on a sample plate. This ritual must be followed for every sample and, therefore, multiple operators are required. In addition, the open system increases the exposure to potentially infectious materials, and requires increased handling of the sample. As a practical matter, the open system also substantially increases the clean-up time and exposure, because a significant amount of blood and bodily fluid leaks from the device onto the floor and underlying equipment.
Certain closed biopsy devices employ tissue filters that are used to collect tissue samples taken from a patient during the biopsy. In many systems, the tissue filter is generally placed within a filter canister and then tissue is drawn into the interior of the filter by a vacuum source connected to the canister. The tissue is then separated from the fluids that may also be drawn into the canister by the vacuum. Current tissue collection systems are difficult to use and do not provide for easy removal of the resected tissue, or core. In many cases, a retrieval element or scoop is required to remove tissue samples from the interior of the filter. However, the tissue core may be difficult to extract from the interior of the filter. In addition, when there are fine tissues surrounding the filter, the retrieval element may not be able to lift or scrape the fine tissue from the filter wall. In this case, more samples may need to be taken, increasing the trauma to the patient and the potential for infection and other complications. Furthermore, the use of retrieval devices for extracting samples from the interior of a filter may damage tissue samples, resulting in potential loss of valuable information about the sample. Accordingly, a need has arisen for a tissue sample collection device that addresses the foregoing issues.